robert@gitpyr.UUCP (Robert Viduya) (05/12/85)
We just got a few 3B2s donated from AT&T and I'm trying to get the tty ports
to talk to an Ungermann-Bass network using hardware flow-control. The network
implements hardware flow-control using the standard EIA-RS232 lines RTS and CTS
in a non-standard way (the standard allows only one way flow-control; the UB
equipment needs two way flow-control). Basically, RTS is used to control the
data flow from the network box to the terminal (or 3B2, in this case). CTS is
used to control data flow from the terminal (3B2) to the network box. The two
lines are independent of each other (deviating from the RS232 standard).
The 3B2s use an 8-pin modular jack (kinda looks like a phone jack). Two of
the pins are marked as "Reserved" (pins 2 and 8), but they are wired to the
RTS and CTS lines (pins 4 and 5) on RS232 25-pin connector.
Now, what I need is some way to control and query the lines. Unfortunately,
AT&T did not distribute the source code the the tty device driver, nor any
documentation on the tty hardware. Can anyone give me any information on this?
On a side note, in /usr/include/sys/termio.h, in the #define's for the
c_cflag field in the termio structure, there are two undocumented flags:
RCV1EN and XMT1EN. Anyone know what these do? Are they related to the above?
robert
--
Robert Viduya
Georgia Institute of Technology
...!{akgua,allegra,amd,hplabs,ihnp4,masscomp,ut-ngp}!gatech!gitpyr!robert
...!{rlgvax,sb1,uf-cgrl,unmvax,ut-sally}!gatech!gitpyr!robertlarrys@ihlpa.UUCP (Larry Schroeder ) (05/14/85)
> Now, what I need is some way to control and query the lines. Unfortunately, > AT&T did not distribute the source code the the tty device driver, nor any > documentation on the tty hardware. Can anyone give me any information on this? Assuming the tty ports in question are those of the 3B2 "ports" card, the tty ports are controlled by the ppc driver and standard Sys V tty line discipline through the Ports board firmware. Standard Sys V tty control flags and requests do not specify any features for access to RTS and CTS for a port. Therfore as for most UNIX Sys V systems the user can not specify their control, the 3B2 "Ports" firmware and driver Does Not provide any user accessable control for RTS and CTS (May be a problem to your U-B controller !?). > On a side note, in /usr/include/sys/termio.h, in the #define's for the > c_cflag field in the termio structure, there are two undocumented flags: > RCV1EN and XMT1EN. Anyone know what these do? Are they related to the above? These two cflags in termio.h define setup for an AT&T tty interface to Teletype's SSI protocol terminals. (This interface is not used on a AT&T 3B2 at this time, but is shown in standard termio.h for most AT&T 3B computers) The SSI ("standard synch. interface") protocol provides a synchronous communication frame which may contain one or two bytes of data or control characters. The RCV1EN flag identifies when set one-byte per frame on receive (two bytes per frame if not set). XMT1EN is similar for transmit... Larry Schroeder AT&T Information Systems -- Network Architecture Department
phil@amdcad.UUCP (Phil Ngai) (05/16/85)
In article <388@gitpyr.UUCP> robert@gitpyr.UUCP (Robert Viduya) writes: > >We just got a few 3B2s donated from AT&T and I'm trying to get the tty ports >to talk to an Ungermann-Bass network using hardware flow-control. The network >implements hardware flow-control using the standard EIA-RS232 lines RTS and CTS >in a non-standard way (the standard allows only one way flow-control; the UB >equipment needs two way flow-control). Basically, RTS is used to control the >data flow from the network box to the terminal (or 3B2, in this case). CTS is >used to control data flow from the terminal (3B2) to the network box. The two >lines are independent of each other (deviating from the RS232 standard). That's gross. You should use XON/XOFF for flow control. -- I speak for myself and no one else. Phil Ngai (408) 749-5720 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA
skip@gatech.CSNET (Skip Addison) (05/16/85)
In article <1345@amdcad.UUCP> Phil writes: >In article <388@gitpyr.UUCP> robert@gitpyr.UUCP (Robert Viduya) writes: >> >>We just got a few 3B2s donated from AT&T and I'm trying to get the tty ports >>to talk to an Ungermann-Bass network using hardware flow-control. The network >>implements ... the standard EIA-RS232 lines RTS and CTS >> ... > >That's gross. You should use XON/XOFF for flow control. > ... > Phil Ngai (408) 749-5720 We normally use XON/XOFF flow control, but uucp is gross. It expects a full 8-bit data path. So do some some other applications, particularly graphics. We'd still like to hear about possible solutions. -- "Here I stand, for I can do no other." -- Martin Luther The Office of Telecommunications and Networking Georgia Tech, Atlanta GA 30332 Southern Bell, AT&T, MCI, etc: (404) 894-6866 CSNet: Skip @ GATech ARPA: Skip.GATech @ CSNet-Relay.ARPA uucp: ...!{akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!skip
robert@gitpyr.UUCP (Robert Viduya) (05/16/85)
> > > >We just got a few 3B2s donated from AT&T and I'm trying to get the tty ports > >to talk to an Ungermann-Bass network using hardware flow-control. > > That's gross. You should use XON/XOFF for flow control. > Unfortunately, using XON/XOFF for flow control means that the user has to go through all sorts of contortions to send an ^S or ^Q untranslated across the network. Besides, in my opinion, flow control should be as transparent as possible to the data being transmitted. It has nothing to do with the content of the data. robert -- Robert Viduya Georgia Institute of Technology ...!{akgua,allegra,amd,hplabs,ihnp4,masscomp,ut-ngp}!gatech!gitpyr!robert ...!{rlgvax,sb1,uf-cgrl,unmvax,ut-sally}!gatech!gitpyr!robert
phil@amdcad.UUCP (Phil Ngai) (05/18/85)
In article <67@gatech.CSNET> skip@gatech.UUCP (Skip Addison) writes: > >We normally use XON/XOFF flow control, but uucp is gross. It expects a full >8-bit data path. So do some some other applications, particularly graphics. >We'd still like to hear about possible solutions. Yeah, uucp is gross and so is emacs. But I thought I heard something about an "f" protocol for uucp which uses 7 bit data paths. Programs like kermit know about such things too. Finally, most of the modern graphics protocols are reasonable and have an option restrict themselves to 7 bit mode too. I run a terminal network at AMD and deal with this issue all the time. In addition, there are new, error correcting modems which usurp XON/XOFF for their intended purpose, flow control (isn't that terrible :-). I am getting ready to try the "f" protocol in uucp. I hope it works. We have two VAXen sitting 10 feet apart which use the switched telephone network to talk to each other. Gross... -- What do you do the day after a peak experience? Phil Ngai (408) 749-5720 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.ARPA